\begin{table}[htbp]\centering
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\caption{Child mortality index -- Subcomponents}
\begin{tabular}{l*{3}{c}}
\toprule
                    &\multicolumn{1}{c}{(1)}&\multicolumn{1}{c}{(2)}&\multicolumn{1}{c}{(3)}\\
                    &\multicolumn{1}{c}{\begin{tabular}[c]{@{}c@{}}Child\\mortality\\0-5 years old\end{tabular}}}&\multicolumn{1}{c}{\begin{tabular}[c]{@{}c@{}}Child mortality\\0-1 year old\end{tabular}}&\multicolumn{1}{c}{\begin{tabular}[c]{@{}c@{}}Child mortality\\1-5 years old\end{tabular}}\\
\midrule
Full treatment      &      -0.011   &      -0.006   &      -0.005   \\
                    &     (0.008)   &     (0.007)   &     (0.004)   \\
Constant            &       0.061***&       0.041***&       0.020***\\
                    &     (0.006)   &     (0.005)   &     (0.003)   \\
\midrule
N                   &         187   &         187   &         187   \\
R$^{2}$             &       0.197   &       0.211   &       0.184   \\
Adjusted p-value (FT)&       0.298   &       0.383   &       0.383   \\
\bottomrule
\end{tabular}
\end{table}
